A home network refers to a home informatization platform that integrates a home control network with a multimedia information network. The home network may be a wireless communications network or a wired communications network, and a transmission medium of the home network may be an electrical power cable, a coaxial cable, a telephone line, or the like. The home network includes at least one domain. A domain is generally a centralized management network. Each domain has a domain master node (DM) and several slave nodes. In addition to being a common node, the DM further needs to be responsible for management of the entire domain, including domain creation, node registration, bandwidth allocation and resource scheduling of the domain, coordination with a neighboring domain or network, power consumption management in the domain, and the like. For a domain that works in a security mode, the domain further includes a security controller (SC), and the SC is responsible for managing authentication and a key. A registered node can perform generation of a key and transmission of data only after authentication is completed on the SC.
The DM sends a media access plan (MAP) frame in each media access control (MAC) period, and a MAP indicates distribution of a transmission opportunity for a node to perform resource scheduling, and a related parameter required by work in another domain. A node finds existence of a domain by detecting the MAP frame, and sends, to the DM according to information in the MAP frame, a registration request to be added to the domain. In addition, after registration is successful, authentication is performed on the SC, and transmission of data can be performed only after the authentication succeeds.
In the home network, the following may occur: A device used as an SC is disconnected, or an SC is disconnected because, for example, a user disables the device used as the SC. Consequently, there is no available SC in a domain or a network, so that the domain or the network cannot normally work in a security mode. For example, a node that newly accesses a network, or a node that requires re-authentication cannot fails to be authenticated, and a node that needs to update a key fails to update the key.